1. Technical Field
The present invention relates to a wireless communication device and a radar detection method therefore.
2. Background Art
As Japanese Patent Application Laid-Open No. 2002-135831 shows, generally, a wireless communication system is required to detect a radar signal where the radar works using the same frequency band as that of the communication system. Thus, a wireless communication system sharing the same band with a radar monitors if the radar signal is present all the time, both before and after the start of its operation in order to avoid obstructing an operation of the radar system.
Also, the wireless communication system, if it detects the presence of any radar signal during its radar signal monitoring, promptly shifts its own operation channel to another channel (i.e., to a frequency other than that of the radar signal). It is difficult to detect such radar signals by using expected patterns of radar signals in advance and providing detection circuits for detecting pattern matching between patterns of radio signals and the expected patterns because there are a wide variety of radar signals.
Furthermore, in order to perform radar detection, a wireless communication device has a receiver for radar detection in addition to a receiver for a communication system, providing many disadvantages in the aspects of hardware size and cost.
Also, a conventional wireless communication system, when performing radar detection, stops its own communication in the same band as that of radar signals to be detected, resulting in degradation in an efficiency of the communication.